Compatible CRAFTSMAN Lawn Mower & Garden Tractor with BRIGGS & STRATTON 6.5 hp Intek OHV Spark PlugCompatible with Champion RC12YC & NGK BCPR5ES Spark PlugsHigh durability spark plug that keeps your small engine running in optimum performance. Premium quality materials resist fouling and corrosion.Superior conductivity for consistent voltage and long life. Stable operating temperature guarantees heat control under a variety of loads. Improves engine start, performance, fuel efficiency, stability and extends engine life. Damaged or worn spark plug that can cause major engine damage if not changed. Replace your spark plug if your engine is difficult to start, misfiring or unstable idle.